Floating device and marker system

ABSTRACT

A device for providing chemiluminescent light from a chemical reaction of suitable compounds in the presence of a fluorescent compound, the device being a self-contained buoyant light unit.

United States Patent 1 Miron Apr. 8, 1975 1 FLOATING DEVICE AND MARKERSYSTEM [75] Inventor: Roy Richardson IIui'lbut Miron, Old

Bridge, NJ.

[73] Assignee: American Cyanamid Company,

Stamford, Conn.

221 Filed: Jan.12, 1973 [21] Appl.No.:323,002

[52] US. Cl. 9/8.3 R; 240/225 [51] Int. Cl 1363b 21/52; B63b 51/04 [58]Field of Search 9/83 E, 8.3 R; 250/462,

[56] References Cited UNITED STATES PATENTS 3,090,977 5/1963 Murray 9/83R 3,360,426 12/1967 Cline 240/225 X 3,576,987 5/1971 Voight et a1.240/225 3,584,211 6/1971 McKayrauhut.... 240/225 3,614,417 10/1971Sanford 9/83 E 3,674,648 7/1972 Soli 240/225 X Primary Examiner-TrygveM. Blix Assistant Examiner-Gregory W. OConnor Attorney, Agent, orFirmGordon L. Hart; Charles J. Fickcy [57] ABSTRACT A device forproviding chemiluminescent light from a chemical reaction of suitablecompounds in the presence of a fluorescent compound, the device being aself-contained buoyant light unit.

6 Claims, 8 Drawing Figures 1 FLOATING DEVICE AND MARKER SYSTEM Thisinvention relates to systems and devices for providing chemiluminescentlight incorporating chemical components which react chemically andprovide excitat'ion for a fluorescent compound.

This invention further relates to a buoyant light marker device and moreparticularly, to a buoy in combination with a tubular chamber containingmeans for producing chemical light.

Under certain circumstances, it is desirable to have a source of visiblelight which is not electrically activated. Light can be provided bychemical systems, wherein the luminosity is solely the result ofchemical reaction without provision of any electrical energy. Such lightis known as chemiluminescent light.

Chemiluminescent light may be useful where there is no source ofelectricity. For example, in emergencies where sources of electricalpower have failed, a chemiluminescent system could provide light. Sincethe system requires no externally generated source of energy, devicescan be made small and highly portable. Moreover, chemiluminescent lightis cold light and can be used where the heat of conventionalillumination is not desired. It is also useful where electrical meanscould cause a fire hazard, such as in the presence of inflammableagents. Chemiluminescent light is also effective under water since thereare no electrical connections to short out. Thus it may be seen thatchemiluminescent light can have many useful applications.

A principal object of the present invention is to pro vide systems anddevices incorporating chemiluminescent components for the provision ofchemiluminescent light.

A further object of this invention is to provide means for containingchemically reactive chemiluminescent components in a non-reactivecondition and means to combine said components when desired to providechemiluminescent light.

A further object is to provide a self-contained, highly portablechemiluminescent lighting device having all chemical components thereinand in which the light is displayed.

Another object is to provide a chemiluminescent lighting device which isinexpensive to make, easy to activate and highly effective.

Another object of the invention is to provide a buoyant light devicehaving a chemiluminescent lighting system.

These and other objects of the invention will become apparent as thedescription thereof proceeds.

This invention comprises a device for the storage and subsequentadmixture and display of a multicomponent chemiluminescent system. Thedevice consists essentially ofa buoy or float which is adapted to hold asticklike self-contained chemical light device. These may be held inpocket like structures in the panel. The light stick tubular containeris attached, and preferably in such a way that it is easily removable,to a buoyant float preferably adapted to adjust the buoyancy in such away so that the chemical light container normally remains in an uprightposition above the surface of 'the liquid on which the device isfloating. Each selfcontained chemical light device consists essentiallyof an elongated, transparent or translucent flexible outer tube and aridged, breakable inner tube which runs parallel to the outer and whichpreferably is joined to the outer tube, or relatively fixed at its endswith respect to the inner tube. The inner tube is filled (wholly or inpart) with one component of a two-component chemical lighting system.The outer tube is filled with the second component. The outer tube iscapped at both ends with a closure which may contain a recess which fitsaround the inner tube to hold it in place and which, if desired, mayserve as a closure for at least one end of the inner tube.Alternatively, the inner tube may be sealed separately and attached tothe outer tube at the ends or along the longitudinal side in anyconvenient way.

To operate the device, the outer, flexible tube of the light stick isbent causing the inner inflexible tube to fracture and thus mix the twocomponents and initiative light production in the sticks. The outertrans1ucent tube thus becomes a lighted wand for display purposes, andit is inserted in the buoy for use.

It is clear that two or more inner tubes could be employed to storeseparately the components of a three or multiple-component chemicallighting system.

The chemiluminescent system of this invention thus comprises the deviceas described accommodating the admixture of at least twochemiluminescent components and providing for the admixture in thedevice of at least two chemiluminescent components comprising either (a)a component containing a chemiluminescent compound and a secondcomponent containing a hydroperoxide compound, either or both componentscontaining a diluent, or (b) a dry solid component containing both asolid chemiluminescent compound and a solid hydroperoxide compound and asecond component comprising a solvent for said solid chemiluminescentcompound and said solid hydroperoxide compound. Any other necessaryingredients for the production of chemiluminescent light, or forlifetime control, or for intensity improvement, or for storagestabilization must of course either be included in one of the two systemcomponents or included as additional components. in particular with thepreferred oxalic-type chemiluminescent compounds of this invention, afluorescent compound must be included in the system.

The preferred chemiluminescent light is obtained in this invention bythe reaction of a hydroperoxide with a chemiluminescent compositionwhich, in combination, comprises a chemiluminescent compound selectedfrom the group consisting of (1) an oxalic-type anhydride of the typedisclosed and claimed in the copending application, Ser. No. 485,920,now U.S. Pat. No. 3,399,130 which is hereby incorporated by reference,(2) an oxalic-type amide of the type disclosed and claimed in copendingapplications, Ser. Nos. 520,052 now U.S. Pat. No. 3,442,815 and 547,782.now abandoned, refiled as Ser. No. 844,557 on July 24. 1969,subsequently abandoned and refiled as Ser. No 211,810 on Dec. 23, 1971and still pending which are hereby incorporated by reference, (3) anoxalic-type O-acylhydroxylamine of the "type disclosed and claimec incopending application, Ser. No. 547,761, now abandoned and refiled asSer. No. 886,395 on Dec, 18, 196. and still pending and (4) anoxalic-type ester discloset and claimed in application, Ser. No.491,896, aban doned and refiled as Ser. No. 619,140 on Feb. 28, 196' nowU.S. Pat. No. 3,597,362 in the presence of a fluo rescer compound, and asolvent. Other suitable chemi luminescent compounds are3-aminophthalhydrazide 3,4,5-tripheny1imidazole, 10,10-dia1ky1-9,9

iacridinium salts, and 9-chlorocarbonyl- 10- iethylacridinium chloride.The latter is disclosed and iaimed in copending application, Ser. No.427,459 ow U.S. Pat. No. 3,352,791. All of the foregoing proidechemiluminesence when reacted with a hydroperxide compound in thepresence of a base. Other cheiiluminescent materials are described by K.D. Gundrman, Angew. Chemie., lnt. Ed., 4, 566/1965.

The preferred chemiluminescent compound of this ivention is anoxalic-type ester selected from the roup consisting of (a) an ester ofan oxalic-type acid ii an alcohol characterized by acid ionizationconstant I water greater than 1.3 X l, and (b) a vinyl ester f anoxalic-type ester. Similarly, in a preferred emodiment thereof, thealcohol would be an aromatic alohol substituted by a substituentcharacterized by a ositive Hammett sigma value. The preferred species ofxalic-type esters include bis(substitutedhenyl)oxalate such asbis(2-nitrophenyl)oxalate, bis(- ,4-dinitrophenyl)oxalate,bis(2,6-dichloro-4-nitrohenyl)oxalate,bis(3-trifluoromethyl-4-nitrophenyloxalate,bis(2-methyl-4,6-dinitrophenyl)-oxalate,bisl,2-dimethyl-4,6-dinitrophenyl )oxalate, bis( 2,4-ichlorophenyl)oxalate, bis(2,5-dinitrophenyl)oxalate,is(2-formyl-4-nitrophenyl)oxalate, bis(pentachlorohenyl)oxalate, bis(1,2-dihydro-2-oxo-lyridyl)glyoxal, bis-N-phthalmidyl oxalate. Thepreerred sub-species is bis(pentachlorophenyl)-oxalate.

The peroxides employed in the components of this ivention may be anyhydroperoxide compound. Typial hydroperoxides includet-butylhydroperoxide, eroxybenzoic acid, and hydrogen peroxide. Hydrogeneroxide is the preferred hydroperoxide and may be mployed as a solutionof hydrogen peroxide in a solent or as an anhydrous hydrogen peroxidecompound uch as perhydrate of urea (urea peroxide), perhydrate fpyrophosphate (sodium pyrophosphate peroxide), erhydrate of histidine(histidine peroxide), sodium erborate, sodium peroxide, and the like.Whenever .ydrogen peroxide is contemplated to be employed, ny suitablecompound may be substituted which will roduce hydrogen peroxide.

The peroxide concentration may range from about 5 molar down to aboutpreferably about 2 molar lown to about 10' molar. The ester of thisinvention nay be added as a solid or in admixture with a suitable olidperoxide reactant or in a suitable diluent, or alteriatively dissolveddirectly in a solution containing the ieroxide reactant.

Typical diluents, which additionally may be used in onjunction with thenecessary diluent of this invenion, are those which do not readily reactwith a peroxde such as hydrogen peroxide, and which do not react vith anester of oxalic acid.

Where a solvent is employed with the hydroperoxideontaining component ofthis invention said solvent an be any fluid which is unreactive towardthe hydroeroxide and which accommodates a solubility of at east 0.01 Mhydroperoxide. Typical solvents for the lydroperoxide component includewater; alcohols, uch as ethanol or octanol; ethers, such as diethyl:ther, diamyl ether, tetrahydrofuran, dioxane, dibutylliethyleneglycol,perfluoropropyl ether, and 1,2- limethoxyethane; and esters, such asethyl acetate, :thyl benzoate, dimethyl phthalate, dioctylphthalate,ropyl formate. Solvent combinations can, of course, )e used asconcentrations of the above with aromatic anisole, tetralin, andpolychlorobiphenyls, providing said solvent combination accommodateshydroperoxide solubility. However, when oxalic-type chemiluminescentmaterials are used, strong electron donor solvents such as dimethylformamide, dimethyl sulfonide, and hexamethylphosphoramide should not,in general, be used as a major solvent component.

Where a solvent is employed with a component containing thechemiluminescent material any fluid can be used providing said fluidsolubilizes at least 0.01 M concentration of the chemiluminescentmaterial and is unreactive toward the chemiluminescent material. Typicalsolvents include ethers, esters, aromatic hydrocarbons, chlorinatedaliphatic and aromatic hydrocarbons, such as those cited in thepreceding paragraph. For oxalic-type chemiluminescent compounds,hydroxylic solvents such as water or alcohols and basic solvents such aspyridine should not be employed since such solvents used in general,react with and destroy oxalic-type chemiluminescent compounds. Solventcombinations may, of course, be used but such combinations when usedwith oxalic-type chemiluminescent compounds should not include strongelectron donor solvents.

When a component comprising a solid chemiluminescent compound and asolid hydroperoxide is used, the solvent or solvent compositioncomprising the second component may vary broadly. Said solvent, however,should preferably dissolve at least 0.02 M concentrations of both thehydroperoxide and the chemiluminescent compound, and for oxalic-typechemiluminescent compounds, strong electron donor solvents should beavoided as major solvent components.

The fluorescent compounds contemplated herein are numerous; and they maybe defined broadly as those which do not readily react on contact withthe peroxide employed in this invention, such as hydrogen peroxide,likewise, they do not readily react on contact with the chemiluminescentcompound.

A fluorescent compound is required for light emission when the preparedoxalic-type chemiluminescent compound of the invention is employed. Forother types of chemiluminescent compounds a fluorescer is not requiredbut may be used to shift the wavelength of emitted light toward the redregion of the spectrum so as to change the color of emitted light.Fluorescent compounds for use with oxalic-type chemiluminescentcompounds should be soluble in the reactive solvent at least to theextent of 0.0001 moles per liter.

Typical suitable fluorescent compounds for use in the present inventionare those which have a spectral emis sion falling between 330millimicrons and 1000 millimicrons and which are at least partiallysoluble in any of the above diluents, if such diluent is employed. Amongthese are the conjugated polycyclic aromatic compounds having at leastthree fused rings, such as anthracene, substituted anthracene,benzanthracene, phenanthrene, substituted phenanthrene, naphthacene,substituted naphthacene, pentacene, substituted pentacene, and the like.Typical substituents for all of these are phenyl, lower alkyl, chlorine,bromine, cyano, alkoxy (C,Cm), and other like substituents which do notinterfere with the light-generating reaction contemplated herein.

Numerous other fluorescent compounds having the properties givenhereinabove are well known in the art. Many of these are fully describedin Fluorescence and Phosphorescence", by Peter Pringsheim, IntersciencePublishers, Inc. New York, NY. 1949. Other fluorescers are described inThe Colour Index," Second Edition, Volume 2, The American Association ofTextile Chemists and Colorists, 1956, pp. 2907-2923. While only typicalfluorescent compounds are listed hereinabove, the person skilled in theart is fully aware of the fact that this invention is not so restrictedand that numerous other fluorescent compounds having similar propertiesare contemplated for use herein.

A fluorescent oxalic-type ester, such as the oxalic acid ester of2-naphthol-3,6,8-trisulfonic acid, does not require a separatefluorescent compound to obtain light. Other typical fluorescent oxalicacid esters include esters. of oxalic acid (1) 2-carboxyphenol, (2)2-carboxy-6rhydroxyphenol, (3) 1,4-dihydroxy-9, diphenylanthracene, and(4) 2-naphthol. Thus, a reactant including a fluorescent oxalic-typeester would thereby include at least one fluorescent compound.

It has been found that the molar (moles per liter of diluent)concentrations of the major components of the novel composition hereindescribed may vary considerably. It is only necessary that components bein sufficient concentration to obtain chemiluminescence. The ester ofoxalic acid molar concentration normally is in the range of at leastabout 10 to 5 molar, preferably in the range of at least about 10 toabout 1 molar; the fluorescent compound is present in the range fromabout 10 to 5, preferably 10 to 10 molar; and the diluent must bepresent in a sufficient amount to form at least a partial solution ofthe reactants involved in the chemiluminescent reaction. If the ester isliquid, it may serve as either the sole diluent or a partial diluent.

The wavelength of the light emitted by chemiluminescence of thecompositions of this invention, i.e., the color of the light emitted,may be varied by the addition of any one or more energy transfer agents(fluorescers) such as the known fluorescent compounds discussed atlength above.

The wavelength of the light emitted by the composition ofthis inventionwill vary, depending upon the particular fluorescent component employedin the reaction.

Additionally, it has been found that the superior intensity ofchemiluminescence is obtained when the final mixture producing theluminescence is maintained at a temperature of between about -40C. and75C., preferably between about C. and 50C. However, temperature is notcritical and the luminescence of Applicants process is not limited tothese ranges.

The lifetime and the intensity of the chemiluminescent light obtainedwith the preferred oxalic-type chemiluminescent compounds of thisinvention can be regulated by the use of certain regulators such as:

1. By the addition of base to the chemiluminescent composition. Both thestrength and the concentration of the base are critical for purposes ofregulation.

2. By the variation of hydroperoxide. Both the type and theconcentration of hydroperoxide are critical for the purposes ofregulation.

3. By the addition of water.

4. By the addition of a catalyst which changes the rate of reaction ofhydroperoxide. with the oxalic-type ester. Catalysts which accomplishthat objective include those described in M. L. Bender, Chem. Revs, Vol.60, p. 53 (1960). Also, catalysts which alter the rate of reaction orthe rate of chemiluminescence include those accelerators of copendingapplication, Ser. No. 577,595, abandoned and refiled as Ser. No. 675,141on Oct. 13, 1967, also abandoned and refiled as Ser. No. 115,734 on Feb.16, 1971 and decelerators of copending application, Ser. No. 577,615abandoned and refiled as Ser. No. 648,932, also abandoned and refiled asSer. No. 56,198 now US. Pat. No. 3,691,085.

While acids are not in general accelerators for oxalictypechemiluminescent reactions it should be noted specifically that acidsare accelerators for the oxalic amide chemiluminescent compounds ofcopending application, Ser. No. 547,782.

More specifically, the advantages obtained by the incorporation of acatalyst of Ser. No. 577,595 may be obtained in conjunction with theobjects of this present invention, by employing, according to thecopending application, an ionized salt having a cation selected from (a)an organic quaternary cation selected from the group consisting ofammonium, arsenic, and phosphorous, and (b) alkali metal having anatomic weight above 22, the salt of said cation preferably being solublein an organic solvent and preferably being characterized by a propertyof forming cation-aggregates when reacted with the oxalic-type ester anda hydroperoxide. One of the advantages is the fact that an excessiveamount of the chemiluminescent agent may be employed whereby a higherquantum yield may be obtained when the ionized salt is employed, incontrast to systems not employing the accelerator whereby such systemswould be limited to a much lower maximum concentration ofchemiluminescent agent which would continue to increase rather thandecrease the total quantum yield of chemiluminescent light.

Similarly, within the scope of the present invention is the concurrentemployment of one or more decelerators either alone or in thecomposition of this invention, or in conjunction with one of more of theaccelerators discussed in the preceding paragraphs. By employing one ofthe accelerators of the preceding paragraph, it would be possible toemploy a greater total concentration of the chemiluminescent agent whileconcurrently would be possible to employ a decelerator which wouldprolong the period during which the light of high intensity is obtainedfrom the chemiluminescent reaction. Such decelerators set forth in thecopending application, Ser. No. 577,615, include for example a compoundsuch as oxalic acid.

When oxalate-type chemiluminescent compounds are used in a solutioncomponent it may be desirable to include a stabilizing agent such asthose described in copending application, Ser. No. 614,397 abandoned andrefiled as Ser. No. 56,084 on June 29, 1970 now US. Pat. No. 3,718,599.

The chemical compounds, components and their reactions for providingchemiluminescent light are described in copending, commonly assignedapplications, Ser. Nos. 442,802; 442,818, and those previouslymentioned, and as such they do not form a part of the present invention.

The invention may be better understood by reference to the drawings inwhich FIG. 1 shows one outer flexible tube for one embodiment of thechemiluminescent light stick,

FIG. 2 shows the inner, rigid tube,

FIG. 3 shows one embodiment of an assembled stick,

FIG. 4 shows the method of activation of the stick,

FIG. shows the use of two interior tubes in a light stick,

FIG. 6 shows a light stick molded to have one end closed,

FIG. 7 shows a complete buoyant device having a solid float means, and

FIG. 8 shows a buoyant device with an inflatable float means.

Referring to FIGS. 1 and 2, the device comprises a flexible tube 1partly threaded at 2 to receive a threaded plug 3 to close opening 4 oftube 1. A second plug 5 is provided to close opening 6 at the oppositeend of tube 1 by a press fit. Both plugs 3 and 5 have a bore 7 forreceiving a tube 8 ofa rigid, breakable material.

In FIG. 3, the assembled device is shown, with tube 8 fitted in plugs 3and 5, which are in turn fitted into openings 4 and 6 of tube 1, holdingtube 8 substantially parallel to the longitudinal axis of tube 1 andrelatively fixed with respect to the ends of tube 1. Tube 8 is filledwith one component of the chemiluminescent system, previously described,for example the chemiluminescent compound in a diluent.

Tube 1 is filled with the second component, described previously, suchas a hydrogen peroxide solution and a fluorescent compound.

Tube 1 is a flexible, transparent or translucent material, havingsufficient rigidity to maintain a shape, such as polyethylene,polypropylene, teflon and the like. Tube 7 is a rigid, breakable orfrangible material such as glass, or a relatively brittle thermosetresin, e.g., thin walled bakelite or other suitable material and neednot be transparent or translucent. Plugs 3 and 5 may be any suitablematerial such as plastic or wood. Plastics are particularly suitable inview of their ease of fabrication.

As shown in FIG. 7, a light stick is used with a float 10. Float 10 isformed from a buoyant material, such as wood, plastic and the like,either as a solid or hollow shell-like structure. If float 10 does nothave sufficient weight it should incorporate a ballast material at itsbase. Float 10 has a receptacle 12 for holding light stick A. Ifdesired, a reflective member or coating 14 can be put on top of float 10to amplify the light emitted by light sticks A. The reflective layercould be a separated metallic foil layer or a coating of aluminum paintor the like material on float 10. Alternatively, float 10 itself may bea metallic material. Light stick A may fit into receptacle 12 bypressure or any suitable clamping means not shown.

To activate the device and provide light, tube 1 of a light stick A ifflexed slightly as shown in FIG. 4. Tube 7, which is rigid, has its endsfixed in parallel relation to plugs 3 and 5 in recesses 7 is bent andbroken at a number of points 9 allowing its contents to admix with thatof tube 1 to being about the chemiluminescent reaction andn to obtain achemiluminescent light emission visible through tube 1. When the lightstick has been illuminated, the device will provide an illuminatingfloat or marker.

As shown in FIG. 5, the device may have more than one breakable tube 8,so that more than two chemilu minescent components may be keptseparated. Such a system is useful where rate regulators such as acidicor basic materials may be used in the reaction.

The color of the light emission will depend on the type of fluorescentcompound and its spectral response. However, the visible color could bevaried by using a colored plastic for tube 1 or colored panel numbers 11or 12.

Referring to FIG. 8, as an example of another embodiment of theinvention, it may be seen that the buoyant member 20 which may be madeof various materials is hollow, has an opening 22 with a suitable typeof closure 24 for the addition of liquid or other type ballast 26. Thebuoyant container 20 is fitted with a socket-like receptacle 28 toreceive a tubular light stick B with chemical light producing means.Light stick B is slightly modified in shape so that it has a pointed end30. As indicated, the inside of the socket-like recepta-- cle 28 havinga nipple or protrusion 32 for engaging an opening 34 in extension of thetubular light stick B. This is designed so that the light stick end isengaged in the receptable 28 in such a way that it is easily removable.

Float 20 could be a collapsable plastic bag, which is partially filledwith fluid ballast through opening 22, then inflated through the sameopening with air after which the opening 22 is closed with closure 24which must then be air-tight.

The construction of the light sticks may be varied so long as the basicrequirements are maintained. For example, tube 8 could be open at oneend and a recess 7 could be the means for closing it. In addition, oneend of tube 1 could be molded closed with a recess 7 as shown in FIG. 6.Moreover, tube 8 could be fitted within tube 1 in any suitable manner,so long as its ends are relative fixed with respect to the ends of tube1.

The invention provides a device for providing visible light whenever andwhereever desired, independent of conventional electrical lightingmethods and without the hazards and limitations of electrical lighting.The chemiluminescent lighting systems can be especially useful inemergency situations where all other forms of lighting have failed. Thesystems do not have the fire of ignitable lighting devices such ascandles, gas, or oil lights.

It will be readily apparent that the chemiluminescent device is notconfined to emergency lighting, however. It can be used at any timewhere a cold, safe illuminating means is desired. It is also useful toprovide illumination where electrical illumination is unavailable. Thedevice is highly portable and can be used for signalling or marking.

While certain specific embodiments and preferred modes of practice ofthe invention have been described, it will be understood that this issolely for illustration, and that various changes and modifications ofthe invention may be made without departing from the spirit of thedisclosure or the scope of the appended claims.

I claim:

1. A light marker device adapted to float on a liquid surface comprisinga weighted buoyant float and a tubular member containing chemical meansfor producing light, the tubular member having an extension, the saidfloat having a socket-like receptacle therein with a protrusion thereonadapted for receiving and removably engaging the tubular chemical lightproducing means, the tubular member extension having an opening toengage the protrusion in the socket-like receptacle of the float.

2. The device of claim I where the float has means for varying thebuoyancy through the addition or re moval of a ballast material.

4. The device of claim 3 comprising a pair of concentric tubes.

5. The device of claim 3 wherein said inner tube means comprises morethan one tube.

6. The device of claim 3 wherein said buoyant member comprises areflective material adjacent said light stick.

1. A light marker device adapted to float on a liquid surface comprisinga weighted buoyant float and a tubular member containing chemical meansfor producing light, the tubular member having an extension, the saidfloat having a socket-like receptacle therein with a provision thereonadapted for receiving and removably engaging the tubular chemical lightproducing means, the tubular member extension having an opening toengage the protrusion in the socket-like receptacle of the float.
 2. Thedevice of claim 1 where the float has means for varying the buoyancythrough the addition or removal of a ballast material.
 3. A light markerdevice as in claim 1, said tubular member comprising a tubularchemiluminescent light stick, said light stick comprising an outerflexible, light transmitting means and an inner rigid, breakable tubemeans, substantially coextensive with said outer tube means, achemiluminescent component in each said tube means, means to close saidtube ends, and means to maintain said inner tube means relatively fixedwith respect to said outer tube means.
 4. The device of claim 3comprising a pair of concentric tubes.
 5. The device of claim 3 whereinsaid inner tube means comprises more than one tube.
 6. The device ofclaim 3 wherein said buoyant member comprises a reflective materialadjacent said light stick.